I'm using 56.5 grains of H4350 at a COAL of 3.380 with the 168 TTSX for about 2900 fps in my Rem 700 with a 24" Benchmark barrel. It shoots sub MOA.

As others have said, use a chrono and work up your loads from a few grains below max. Somewhere around 2900 fps should be a safe maximum for 165/168 grain bullets.